MagicalNekoLenLen likes to draw anime girls with giant tits, and sometimes he likes to draw breast expansion vignettes, like this one. Himari (pictured) and Lily are original characters. Himari has huge tits, Lily’s flat as a board. Although sometimes (1, 2) people do “breast swaps”, where Lily is depicted as being blessed with a massive rack and Himari hasn’t got enough boobflesh to fill a Dixie cup.
Anyway, in this image Himari doesn’t wind up with small tits – quite the opposite. She’s all set to get her boobs measured and then whammo! She finds her breasts growing by eight or ten cup sizes! That’s the good stuff right there! Click the image for full size and details at deviantART.